The window for Congress to approve an immigration overhaul is closing.

President Obama has made it known that his patience has worn thin as House Republicans dabble in the issue.

WASHINGTON -- The push-pull of immigration reform is intensifying as Congress prepares to return to work for one of the last few legislative sessions before the midterm elections.

600-plus Business Groups Press For Immigration (Wochit)

More than 600 business organizations, from the U.S. Chamber of Commerce to Apple to McDonald's, have sent a letter to House Speaker John Boehner pressing him to move on immigration legislation this year. Boehner and GOP leaders unveiled a set of principle

More than 600 business organizations, from the U.S. Chamber of Commerce to Apple to McDonald's, have sent a letter to House Speaker John Boehner pressing him to move on immigration legislation this year. Boehner and GOP leaders unveiled a set of principle

The window for Congress to approve an immigration overhaul is closing, but House Speaker John A. Boehner continues to suggest that action is still possible -- even as he mocked his colleagues who find the hot-button issue too difficult.

"Here's the attitude: Ohhhh. Don't make me do this. Ohhhh. This is too hard," Boehner said, mimicking a whining tone, at an Ohio luncheon, according to the Cincinnati Enquirer.

Boehner is racing the clock this summer, not only against the coming November election but the threat that the White House will take administrative action if Congress fails to act.

Here's the attitude: Ohhhh. Don't make me do this. Ohhhh. This is too hard.- House Speaker John A. Boehner

President Obama has made it clear that his patience has worn thin as House Republicans dabble in the issue, almost a full year after the Senate, which is controlled by Democrats, approved a sweeping bipartisan immigration law overhaul. Obama has directed the Homeland Security Department to review the way immigration laws are handled, and emphasis of that report is expected to fall on curbing deportations.

Obama also faces a time crunch. Advocates for immigrants, including those camped out in front of the White House this month, have tired of administration promises, particularly as deportations have separated families. Labeling Obama the "deporter in chief," as some have done, is not a legacy the president wants to stick.

But here's the rub: Every time the White House threatens executive actions, it drives Republicans further from any compromise with Democrats. Tea-party-aligned Republicans argue that the president would merely pick and choose which parts of new legislation he would enforce.

Twenty-two Republican senators raised the trust argument this week in a letter warning Obama against the Homeland Security Department review.

"Our entire constitutional system is threatened," they wrote, "when the executive branch suspends the law at its whim."

Most observers believe that the opportunity for immigration reform during this Congress has long passed, and that this summer will provide a lot of talk but little action.

Then again, Boehner knows how important the issue is for the Republican Party as it tries to broaden its base of mostly white voters, especially heading into the 2016 presidential campaign.

The short legislative calendar could present a venue for testing GOP immigration reform bills.